JeromeS13's 818S

[metalmaker12]

Nice man!

[metalmaker12]

Nice man, pretty much the numbers I am going for but reverse once I get my motor back together.

[longislandwrx]

Very nice numbers. That thing is going to pull HARD.

[Frank818]

Now drive.

[JeromeS13]

Added current 818 parts list to end of Post 1.

[JeromeS13]

Initial shakedown videos. I think the springs are a little soft. The rear squats like crazy and the front end dives a LOT on heavy braking. I also need to address the air to water intercooler setup. My intake temps were reaching 180-190 towards the end of my sessions... The Federal 595 RS-R's also aren't as sticky as I was hoping. (I peaked at 1.38 G's during left-hand turns and -.93 G's on braking). Aside from those issues, the car ran great and it was a BLAST!!!

[JeromeS13]

[JeromeS13]

[Frank818]

Nice stuff Jerome!

Tell me a little more. Besides crappy cornering grip, did you manage to reach/overshoot other limits? Full suspension travel, tire spin in 3rd gear, lose bolt, broke a part somewhere?

About your grip issues, try out the Yokos Advan Neova AD08Rs.

[metalmaker12]

Yeah front end does tend to dive during heavy braking, and those tires are like mine, not very sticky. Looks like fun, can't wait to get back to that. Get another set of rims with Hoosiers for the track and be done with it.

[Frank818]

What about the springs on the street? Are they still too soft for street driving?

Might want to try out the R's, then.

[JeromeS13]

Nice stuff Jerome!

Tell me a little more. Besides crappy cornering grip, did you manage to reach/overshoot other limits? Full suspension travel, tire spin in 3rd gear, lose bolt, broke a part somewhere?

About your grip issues, try out the Yokos Advan Neova AD08Rs.

I wouldn't call it "crappy" cornering grip. I think 1.3 G's on street tires isn't that bad... I'm scraping on the inside front fenders on heavy braking and bumps (might have to adjust my wheel spacing), even with -2.5 degrees of camber. The rears are rubbing the aluminum on the very top. Nothing broke. My coolant temps were no higher than 196 (thanks to my Ron Davis radiator) and my oil temps reached 248 (no oil cooler). This was a trial run to see where I need to make adjustments. I'll finish this season out making subtle changes, and change tires, aero, etc. next season. As metalmaker pionted out, when I buy tires again, they'll be a dedicated set (more than likely).

Yeah front end does tend to dive during heavy braking, and those tires are like mine, not very sticky. Looks like fun, can't wait to get back to that. Get another set of rims with Hoosiers for the track and be done with it.

[JeromeS13]

What about the springs on the street? Are they still too soft for street driving?

Might want to try out the R's, then.

The springs feel fine on the streets.

[Frank818]

What right height you're at?

I think your tire setup is 235/40/17 and 265/35/18, right?

I am taking notes of what results people get with their setups, to give me an idea once I'll be there myself.

[JeromeS13]

What right height you're at?

I think your tire setup is 235/40/17 and 265/35/18, right?

I am taking notes of what results people get with their setups, to give me an idea once I'll be there myself.

Correct. FFR recommended 4.5" ride height.

[Frank818]

According to you Jerome, if your 215/40/17 weren't BOed, since they are lower than 235/40/17, do you think you would have rubbed on the inside front fenders as well?

[JeromeS13]

According to you Jerome, if your 215/40/17 weren't BOed, since they are lower than 235/40/17, do you think you would have rubbed on the inside front fenders as well?

I'm not sure. It would only be an assumption.

[C.Plavan]

Time for some R spring rates The squatting and diving will only get worse with stickier tires.

[JeromeS13]

Time for some R spring rates The squatting and diving will only get worse with stickier tires.

Well, here's the thing... The S spring rates are 350/275. The R rates are 300/500. That means, if I switch to R spring rates, the front gets softer.... I'm not sure how I feel about that...

[Frank818]

Would the shocks' stiffness adjustment help when diving? Cuz it's one adjustment, so I believe it's both compression and rebound, making them stiffer may help, maybe.

[Scargo]

Seems like you also need to get the oil temps down. Arizona's not a good place to be marginal. I remember the first time I was in Phoenix and left my tools in the sun...
What are you thinking about doing to the AWIC? I plan on running it.
I'm jealous, of course. Like the blow-off noise. Mine is still on hold; waiting for the STi to get off the lift, onto the track and out of the way.

[C.Plavan]

Well, here's the thing... The S spring rates are 350/275. The R rates are 300/500. That means, if I switch to R spring rates, the front gets softer.... I'm not sure how I feel about that...

Hmmm- I did not realize that. That's strange in my book.

[Frank818]

My book's much less impressive than yours, but looking only at the spring rates, it sounds odd indeed.

Like I mentioned, wouldn't the shocks do anything about that?
Or if you lower your ride height say to 3in, it may dive less.

I am very curious to understand what's going on here and which variables would change that.

[metalmaker12]

S springs are fine for street driving, get rears R's for the track. I am going to get the R rears for track days.

[JeromeS13]

Would the shocks' stiffness adjustment help when diving? Cuz it's one adjustment, so I believe it's both compression and rebound, making them stiffer may help, maybe.

I'm not sure. If/when I change the springs, I'll more than likely turn the shocks to full stiff.

Seems like you also need to get the oil temps down. Arizona's not a good place to be marginal. I remember the first time I was in Phoenix and left my tools in the sun...
What are you thinking about doing to the AWIC? I plan on running it.
I'm jealous, of course. Like the blow-off noise. Mine is still on hold; waiting for the STi to get off the lift, onto the track and out of the way.

Yeah, this was only a test. I wanted to make sure I had sufficient cooling capacity in the water cooling system. I think I'll be trying a water-oil cooler for the oiling system.

For the AWIC, I'm going to upgrade to a higher flow pump (from the Bosch 5 GPM to a Meziere 20 GPM), tilt the intercooler core (to remove any trapped air), and I need to make a block off plate between my radiator and where I have my reservoir mounted. If that doesn't help a good bit, I'll be updating the heat exchanger and intercooler core itself.

My book's much less impressive than yours, but looking only at the spring rates, it sounds odd indeed.

Like I mentioned, wouldn't the shocks do anything about that?
Or if you lower your ride height say to 3in, it may dive less.

I am very curious to understand what's going on here and which variables would change that.

I need to keep the ride height at a comfortable street setting. 4.5" is about as low as I can go.

[Frank818]

Meziere 20 GPM

That's what I currently use on my street car. Very stable, always cool temps. I don't recall reaching more than 95-100F on the streets. Makes my water roll over 7 times per minute (3gal tank).

tilt the intercooler core (to remove any trapped air)

What's the theory in this?

[JeromeS13]

What's the theory in this?

Right now, the core is parallel to the ground and the inlet/outlet are at the center section (vertically) of the core. It's possible that I have air trapped in the top of the core, which makes it less efficient.

[Frank818]

So by tilting the intercooler upwards it would allow the outlet to be the highest point of the intercooler core so no air would be trapped?

[JeromeS13]

So by tilting the intercooler upwards it would allow the outlet to be the highest point of the intercooler core so no air would be trapped?

Correct. What core/heat exchanger are you using? Do you know your actual intake temperatures? If so, what kind of temperature differences are you seeing at peak boost (between the intake temperature and your ambient or water temperatures)?

[Frank818]

Correct. What core/heat exchanger are you using? Do you know your actual intake temperatures? If so, what kind of temperature differences are you seeing at peak boost (between the intake temperature and your ambient or water temperatures)?

I am using a small home-made 2.25" in/out cooler from Schimmel Performance in PA (VW-Porsche). It's about 12x8x3, it's part of my to-do's to check on the dimensions cuz I want to keep trace of it in case I decide to change for something bigger at some point. It's rated at up to 500hp.

Yes I do know SOME temps differences, however it's probably not what you would want.
I remember taking logs of that in the past at different intake temps (sensor 1in from the air filter) vs cooler outlet temps (3-4in from manifold and 3-4in after cooler outlet). I would have to find that excel file back IF you are interested in this but I doubt, see below why. The results of that log showed that my after cooler temps used to be on average just a few degrees Celsius above air filter intake temps, in all street situations.

The reason why I think it's not what you want is that these temps were a mix of boosts. Vacuum and boost numbers, not all at peak boost. And we know peak heats much more.

On my next ride I'll take a closer look after a few seconds at peak boost what readings I get. My guess is add just a couple of degrees to my above figures, cuz I've never seen the temp needle move that much, but then again I don't peak boost for a long time since I'm on the streets.

[JeromeS13]

Gotcha. Yeah, I'm mainly interested in deltas on extended boost runs. At the end of the straight in 4th gear, I'm seeing 59-68 degrees above the system's water temperature.

[Frank818]

You use engine water temp to compare your cooler efficiency?

I'll check on a 4th gear boost with the longest rpm I can afford on the street loll. But I can probably do it once, then wait for another stretch or moment without cops and cars around, which lowers temps.
Mixed boosts last w-e I got 10-15F above air filter temps.

EDIT: My air filter temps were about 80-85F last w-e. Engine water was about 170-180.
EDIT2: As an example, when I was using a supercharger without a cooler of some sort, my intake temps (just before the manifold) were about 110-160F. Not stable very much. Now with a turbo and cooler, it dropped under 100F.

[JeromeS13]

You use engine water temp to compare your cooler efficiency?

I'll check on a 4th gear boost with the longest rpm I can afford on the street loll. But I can probably do it once, then wait for another stretch or moment without cops and cars around, which lowers temps.
Mixed boosts last w-e I got 10-15F above air filter temps.

EDIT: My air filter temps were about 80-85F last w-e. Engine water was about 170-180.
EDIT2: As an example, when I was using a supercharger without a cooler of some sort, my intake temps (just before the manifold) were about 110-160F. Not stable very much. Now with a turbo and cooler, it dropped under 100F.

No engine water temperature. I use the AWIC system's water temperature to compare intercooler efficiency.

[Frank818]

Gotcha. Makes sense! Loll
I don't have a sensor there, however.

[Brando]

Well, here's the thing... The S spring rates are 350/275. The R rates are 300/500. That means, if I switch to R spring rates, the front gets softer.... I'm not sure how I feel about that...

I also am having major rubbing issues up front with hard cornering or braking. R ride height and softer springs isn't helping. My only hope is removing the 3mm spacers, set shocks to stiff and tighten springs. I still think after I do all that I am going to rub

[Frank818]

Brando, you're running Hoosiers R6s 225/40-17 Front?

[Brando]

Yes

[JeromeS13]

Maybe I'll try running 400/500 springs...

[metalmaker12]

My front tires are not rubbing but the noise does dive slightly under really hard braking. It still dives much less than any performance car I have driven so it's not really that big an issue. My noise rubs the ground under extreme cornering, which in my autocross was much more sharpe tight turns compared to what Jerome was running through. My ride height is 4.25 all around, so the 4.5 would prob fix the rubbing along with a front sway bar. I also think with the R rear spring rate the car would not dive as much either. I also pulled around a 1.4G before it started to loose grip with Yokohama S Drives. I wish it kept running because it would have been an awesome video and great feedback.

Front tires: 215/40/17
Rears 255/35/18

I agree 400f and 500r spring rate for track driving maybe ideal.

[Frank818]

Just for comparison Metal, what performance cars have your driven?
And I believe you meant "nose" and not "noise" loll